West Ham went down 2-0 at Watford as David Moyes' tenure as manager got off to a losing start after a goal in each half at Vicarage Road on Sunday.
Will Hughes turned home Andre Gray's scuffed shot in the 11th minute to put Marco Silva's men in front and Richarlison netted the second in the 64th minute to wrap up the points.
The visitors, who had struggled to get striker Andy Carroll involved, rallied after going behind and would have been level before halftime but for some fine saves by Heurelho Gomes.
After West Ham's Cheikhou Kouyate missed another glorious chance, Watford upped their game and the pressure told as they scored their second.
Watford climbed to eighth on 18 points, with West Ham stuck in the relegation zone in 18th on nine.
Watch the highlights in the video above